Protective sleeves that are longitudinally opened are known to be used for surrounding elongated members and protect them from cuts, abrasion, radiant heat, vibrations, induced wear and other harsh environmental threats. The vibrations can lead to wear of the elongate members and, consequently of the sleeve itself. Such protective sleeves are also known for routing elongate members.
Besides this, such protective sleeves are used to absorb the noise arising from vibrations between cables, especially in automotive industry.
Protective sleeves that are longitudinally opened make easier their placement around cables to be protected. These protective sleeves, even though are longitudinally opened, are elastic in their behaviour and return back to their tubular shape automatically when they are in the rest position. These longitudinally opened sleeves are also known as “wrap-around” sleeve.
When positioning within protective sleeve, the wiring or cables are also held together in a neat bundle, allowing a multiplicity of different items to be handled as sub-assembly, thus saving time and effort during integration of the items into their environment.
Protective sleeves may be made by weaving or knitting yarns into a weaved or knitted textile and then resiliently biasing the two longitudinal opposite free edges of said textile toward each other in order to impart a tubular form to the textile and to define an internal space for receiving elongate members. Biasing may be effected by heating the yarns under the final shape that is sought after. For example, biasing may be effected by heating the yarns when the textile is wrapped around a cylindrical mandrel or is placed in tubular form inside a tube, wherein the yarns take on a permanent set confirming to the shape of the mandrel or to the shape of the internal volume of the tube. The textile is then cooled down still wrapped around said mandrel or in tubular form inside said tube. This thermo-forming step may be performed only if the sleeve comprises a monofilament yarn in a plastic material. This thermo-forming step imparts a shape memory or elastic memory to the textile and therefore to the sleeve. The textile used during this thermo-forming step is in the form of a strip in order to form a sleeve that has a longitudinally axis and a transverse axis, the length of the strip being higher than its width. The sleeve is heated at a temperature that is generally close to the glass transition temperature or the softening point of said plastic material(s). One example of a thermo-forming step is described in U.S. Pat. No. 4,929,478, the description of which is incorporated herein by reference.
Besides this, when considering acoustical dampening materials and protective coverings, for example for use in automobiles, weight, thickness and expense are often limiting factors. With such reductions in automobile size, weight and thickness of parts, higher expectations as to the performance of the interior compartments, and inclusion of more electronic parts and wiring, selecting the most efficient, yet economical, acoustic isolation materials has become even more important. However, reaching certain sound reduction expectations with a sound reducer that is easy to manipulate and durable enough to withstand use in harsh environments remains a challenge. Various woven, knitted and non-woven materials have been considered for such use. Applicants have found that identifying sound reduction materials that are easy to manipulate and durable, as well as beneficial for other factors, for example minimizing abrasion resistance remains challenging.
In the automobile industry, for example, wiring is known to create undesirable excess noise. In efforts to reduce such noise, automobile wiring is traditionally wrapped with sound inhibiting tape. Additionally, wovens and non-wovens have been wrapped around the wiring to reduce noise levels transmitted through the frame and body of the car into the interior car compartment. However, Applicants realize that there are many challenges associated with these applications for acoustical dampening.
In one example, a nonwoven such as felt has been wrapped around automotive electrical wiring to protect the wiring or reduce the sound resulting from the vibrations occurring in automobiles. Tape is often used to wrap around the felt surrounding the wiring to secure the felt in place. In situations such as these, however, the felt and tape application has a number of disadvantages. By way of example, the felt may display undesirable wearing due to the abrasion and temperatures to which it is exposed. Additionally, the felt does not easily fold around the wiring and/or other automotive parts, and furthermore, securing the felt with the tape is cumbersome, time consuming and labor intensive. Improvements have been attempted to alleviate the need for holding a wrapping, such as the felt, in place on the wiring; however, such improvements like adding fasteners can add unacceptable expense. Also, the external automotive environment can often be extreme with heat and durability being factors in the usefulness and sustainability of materials when applied in such an environment. Often, when a wrapping is used to protect automotive wiring, the wrapping does not offer desirable sound reduction qualities and when wrapping with sound dampening is used, it is often not acceptably abrasion resistant.